SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '333caee2f83f9120d3e4b62f050e06c5ca5489c55f901a451a6a13a31b220295' 
  AND token = 'soetl9k0fdOQRotCadI2MZvYPljMi39PdRAukPpF3fo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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