SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c9bb12ca9fbd79fa8c7e4f965ad7fa01300523d9a1b2dc348241cb4439222d31' 
  AND token = 'lcR5gImNTdOGbKAYPp2/UbYDElJsesHU4tfj60Cd6XM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}