SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '962ffd7627848bd651c5101378ab859ef2bd96f6cd383c9bc94b22fb0e6644b6' 
  AND token = 'yJTcSGj2NRVVYqPr86LztakPhBFDXwvndSehbgBRBqE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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