SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cfaa73a8c9122c51c131cf962e2372760446bf75a319349ed21e9054670b9000' 
  AND token = '8/EaYqynSi6Cmeq06xz2xA5tGeyFYtRvNww2F3aElW0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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