SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '536a61982cb029781a008c008a7ccfc4ff510011ac0438811368f4cc5f06e296' 
  AND token = '49fxrWyB5T9tW1Alp58xbVpP+44fVsuwUE/ll/OvpHw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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