SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '846c7af81b2c47a6c91826d5db582b3ea01d89a78843574afbe289280935afb2' 
  AND token = 'H+xtpNS5oY/gMBzqQ/WOLF9E6Aixv2L6t+3TNOougpQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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