SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f4353b988401bc41e0ed827b676dab87a175cd71c2e39c308cae8c454a5ac562' 
  AND token = 'C3s6au/FOWdaKEjjYHpoEpTeLYjvGP/lHxEFm7T7xGY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}