SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bec347906228f9037b09a4971f3c4904b70b657e7b352e2947c563a88959635d' 
  AND token = 'n+NzLXgYqcyDW9Ps9ojvS5w4/DPxQl4vz3cB+gv6ZQk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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