SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '61131d351b07a038e9ae7b8d1bd1fee86e23038dd38cd6b048a40cea3a43d64b' 
  AND token = 'kyJB0epTM/LHzBJcyTWKbId6zCqjUfWYghG3LldPaVY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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