SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '0a7f2114401dbcee2e82c2d4f9bd4d53ac1b5eff212d86b63570611aad27ca7e' 
  AND token = 'Ofc/2JQmKlNipUb8+hCH0QuP5vdpVWP+wCh/+g8Szdg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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