SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ede4060c19d4fbfa90f6c1580caf859aaae0b2f0cb077648292372799a22d292' 
  AND token = 'cxfPBJ5021xKOL+WV18XXR+Lwdk0DzIJicFarpWQ8is=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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