SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd6816ad87136f04e692b251c5d8fa8877c4cf2ec452e918ecb1d7dfae99fbd34' 
  AND token = 'DRVyqXlyYLCUYzDjB0BonkEUWaTqc0GDKCYP5I2jEIg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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