SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b4f22a54af7b5257e77c4f48b8554efc7b854d6ed847dbf101b0efc7aa32a1a2' 
  AND token = 'duVKq5xxVedhIiEkqbj630u2u3JmHhMGYxliMBiUzmE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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