SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8e721ccb3a9acd778f5feed27d41065bc716d03187beeca1e3bfd6bb744b1f4f' 
  AND token = 'sxw/BIebqRhELB+cp8l0vpj9tcwvDRgUCAD45ZylbgQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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