SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ffcd1e1aba504d0088fe6e578c92d30dfc07f1867cb993a0c8ceb1949271108c' 
  AND token = '9dLoJXbg7wUpiVUke23eMmWAl/FEFSapMxgYPtuzIwI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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