SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c011937060ccf9cfa6247cb5f3a6adc3d47b21d68ace7c88b8b8894f282aba5e' 
  AND token = 'Nee7ElAblBSRh78AdOFUkqFWPj+mOEnSV/PQ5Vqc2vA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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