SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '56db38717a92e05d28f91ab636c1d69009939e48f7cd15e7c94eee0b15eb2ac3' 
  AND token = 'UTtGcnYx4DLAGZqHZ03MJB2lrKs6uL8vRzOjNmp97jY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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