SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5314df5b8866ff764c032c82f6eb24c2a078982adaf25daa3bbdeabcf503b0bf' 
  AND token = 'HwDCs4RRwVfO6MoUcdxQb1/HHLODVdtAugXo+gLBIAc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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