SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd7200631432e76c5a8c0514208dd0e687cd9b8d97f202bfc06d4d6b93392600e' 
  AND token = 'fnq1B1Rah855YNwleJirATZHtzABVtjzNFHFLDBk64A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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