SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7fccf74c1a8ca1b948fcd5467ba2cc6c2f5fd230e246dfd98c4316975e24d5d9' 
  AND token = '0zgCLI4eVcibPMeBl9zt6jBNdAc2Bu7eGC3Us63tKZw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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