SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fb34e7966bbea4559e8c6ffc0042e8b0a6f9902cfda2416f7916ce1723cb5736' 
  AND token = '53ukLEPhdEtABP5oidAIYvDFEsmDWqJdmPfh45exqCs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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