SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '946247435d3afbc3f4aac0b4469b1b8257ec01ee7f9a76a491bff47000d93827' 
  AND token = 'BPE7LCKtwAPfilnS8fNLuS+MWZm7AqoSiVBUdVOqaDs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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