SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5d159ff4443c609282f17b5e45d8be1b691a5bee6f331f9c7b42f7ba0b2b6b0b' 
  AND token = '/q/4B/097Jv/mptckPYxSGXEM1PH3jvyRn3HVhzrhTo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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