SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ddba6a0eda83fe0263a5b9ad53acc6105f3729c3240272ba7102b44d820aba60' 
  AND token = 'kX868ZGjSNyHlchav6DSsFHQYbpkGRZcYYOIc/d6Lhw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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