SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b33385b33be7a467acb407f11e5161a3f93db1b983f5052d25431599fd8748ed' 
  AND token = 'PwngYrk6KwfNh7BFEhzuwJcgXq2P0xR51oZ4Q+9yOc8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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