SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '53c16c524ec38771c1665e818c640923517eddc06b91746e6b491c39ab73e62a' 
  AND token = 'heZ0EtHvbIUTTUq9UgVQMOAhLU7iOZwNPs1V/Nc8aMo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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