SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7718aaee6fa9bc236032141b3f86717620b916b714ad8cdc8a11bebd555fe3e0' 
  AND token = 'WtuWjysKX7bLZO10/FNE980TfALMjySlFTrGpt+Ozfg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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