SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2bffa8f7b3a4eaf3862271bb976a950f92524ef604c85cf62a2ce2ae1f1f5724' 
  AND token = 'vZJhcYLbJ5FexB1CzPC4Ks6PIMNuPzVZIfUsVoWmfjc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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