SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a89d7cfaba4f465309b12ba0b932b89b1d69635d01bc01333d80b0cfc55e0f77' 
  AND token = 'Dc+ZKEzUD+mF6xBNW7uADx8qdqVMKfhRzd//4gwufTA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}