SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd039df08d2ba667002e8225fca949c2784f427debdaf08071d86dcb6d1cadf92' 
  AND token = 'UtEzvvWY8e6gFXqubDLvDfObrieq29yZyKfVxuBfXIQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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