SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9ba88d9319f475ba76d719a951b02a19c83a2185e2363ac05ab4050576064969' 
  AND token = '6sevhBhnrasx8nICYt7g5xBpWu9RODja9hkqaMNuD90=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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