SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '134864041a4b481bf14f87f0d53275b206450c48fe82e46c29cc1ee1737444af' 
  AND token = 'GtaUCPp6i+mp0vhC1DDsza13YsOQE49Qy3l0VgnA4GY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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