SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '34523c6fa04d4e6a9988a0781b53d3453445fe75f9de64e3a13cac17e9e909c6' 
  AND token = '7OH6WJuoYk4tuVBIRuSyargjDOmE/qxH9T3ir6sXTmU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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