SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0791923ab84c168e8ef9ebf852cc0e27d7e0ec7471899bef2b98ccdc36efe9ac' 
  AND token = 'i25YfYUuy+AjiGhXR3kOr8NbkYll7vjxVJSwduYZEII=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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