SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5adf7cf0cc6f6d5fd22b9f7ac4177b9814a6122f88e257b20eec6595305a0953' 
  AND token = 'uORbfy2qzKmN4VMwNLWPvcAn+xDyVqgd+G36xW3mvXo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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