SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e08ba888ef60d8fd1dffda5c97ef157eb50ec41018837a4482a440e80e5e6f26' 
  AND token = 'PC1EZDpHi8lgRCxxD4hp0SG7DgPAKjFq5DMy9tJnb7o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}