SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd238bf0ea471817c53f546d1912a4074c087a95463e4a095b799aa561cb77c79' 
  AND token = 'ZNaBj82i1nCjb+hhiU9miuvbfLlhc5iy+tZ2c671N3A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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