SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b11bc540cc73996943daff2022906367652c73e6b2df2226124f76c0c7136a87' 
  AND token = 'moqJ4Twla8V1CDmHcoRE4pKtUHTsmXzVqY6+NdJdcpA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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