SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '190d35e08500a256e05d484f8549905cf5da0b489f883b9deafad0bcdbe19e47' 
  AND token = 'Z6MNbsUkisBlJJpyjKZxLAEKHWumO2pssT1NowchQBo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}