SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ccf703cf9ac7359a132fdef526937e9a4944d3050e284a41cf58fbebf9efd1a8' 
  AND token = '1M50LT1Mvi2KqySfnL5QbA003VPEoUemkaz/YQVMSmA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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