SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b18b56e07676dbf12f4908bb0706a7cc747623ca764c16472d5c023d45fc56f6' 
  AND token = 'kqb27p1pNuP94dDIxEXrAoLVmL+tTwk+ly0zYq7n/sI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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