SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0086ff0ea9857ed63c9a1a4f4de03f227b69fc5b626d4d441183d9e5bac43ddd' 
  AND token = 'nt7vgeLRDGba/JXm2pXD2NTCzx8qoVIKYJgGvIo61Nw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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