SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '76282420fbf788c7b9d553eecc7f19a1101f606f339957a8b3a4360ba324863f' 
  AND token = 'rpQoyKqCMa4xG8K5cNK4jvnEUR2cd/JeSeTzGbPKV7Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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