SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '66bb08b67a4615508c385be934cab2f6e124269c917ae9b8dbace26a44062fef' 
  AND token = 'RRVkjj00dRitCUufepU8byUs3YxD2UIEZn5BWixAHN0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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