SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9a76176f89b2ab85decccbef58aa00816f36734758c89a8e59ad5a24512d18a7' 
  AND token = 'Wv/BzQNR+4Xbd4GgFCU44Yomf0eEnqOLF+WOhQCLD/o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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