SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7211794539c89df75b574ef25b6938ac2aadcbccb72ac4e0191698f98b6aef8b' 
  AND token = 'Kp4n0+GbGV38sZjzGm20Rw1ep0o0mn3sEHUqYN3jufg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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