SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7ee2807884a0b7e4eceadaa97143325c34fde2bf75d56e4683be15fbc3d6251c' 
  AND token = 'f6wNbRuVF4ktCCBWZdDjDvIvl1sb/5jtmVDMLXoBWdE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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