SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '23031be13d1e686e2f14addbf91a778797706c05bcdc07b2b3bcffb2ca7ce3cf' 
  AND token = 'q+2Mm8bVqPQ8wjgjCL8gBCE2m/nwqcmqQUAtCvDFEEo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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