SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '34cb54d6b3a488e738e09055eb65ac57664061a25092b6344d15fe9cbe602670' 
  AND token = 'v/6q7vuQhwHDI11Ij4Yx0HO7bFbWYNYviaRFI1/R9VU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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