SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e039b1a6b937dc67710329babda3d605a5d9c135f5c261402041806d6698e944' 
  AND token = 'wHW5vgSre3SJCtsBfw02rp8AqWTfhn4FugzIPO61NTU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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