SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd5e46d4c5697dfbad962873698cfdff74764f9b7e03798eaf851dfacd43d3215' 
  AND token = '/hZA7hX3i6TChs17M6zqTJVDUiysmNBIXPTHFYu9p5s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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