SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '92375e67b97d0b5fb94eaebbb45a27d4f04cea7fbdbbb6c3a054cc5ef9f56f46' 
  AND token = '5BoGqGAZOs4JO4FB37aCB8Tbe7P8tuZ88Lz0yLRsWcQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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