SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a0ce514e52a5cff918cd91ddef8e6b9f1740aa1b0c3fc1ff925a44fd581a01ea' 
  AND token = 'beLI+M8i4iXLyEsk+98ZP3WETvaBfuNerVk6R7rIiUY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00059

JSON explain

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