SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bbe5882927879aae69175ccda9e08d7a5769a51ae39caeeeadf366f8cf9d700c' 
  AND token = 's8zYcAc9eFxcCG6JhSUBOzRBuwrvUeQ4ss+9Pvqt2IE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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