SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2aeecf92eb379dea1121d985d1e0a09618ba56e4abc21d15845f37683da8b5fb' 
  AND token = 'Qv41Qzv2jTQrzKJc2ulG8lQ8t8ptiJC2uOHK+EKW7AM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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