SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3190ca6c9dc4677ef1a9e11e1fff04771906512aef0e270b3a5b943d17dd6d0c' 
  AND token = 'X4IgsDra8iiT7YgIUBiMZuEX1XZBHAQioZZx/vs0rsk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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