SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4bb66d044a65fa63437c700ea858faceae798fecbfc2e99c70a8751c13a84aa9' 
  AND token = 'K8Q8ovLTGS+CAucrLDWMfpCxhQPV8lE6vf3sTjP4ibQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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