SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ff28b5d95a0124269d3cf34d5ffbb7c80eb90f8088b672e28586f7cb9443f2c7' 
  AND token = 'BC1phPR/MYPDVpPB3X1vPX40ad00Af+zrAGls+mS3Z4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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