SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '86d5b919c6b13cbda3f0c12423865dd8b869c14145aec5dc517868f8580e654e' 
  AND token = '7hMnBKFwcIMk0Z6IlbSEiv8c4XetE7ZeHAAZJp2JBjY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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