SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '563ff5ad13f5fb901bc5f1918406b882571d210d0d590b129f2a9fac68b1cacc' 
  AND token = 'SwgmbkT1WGddgaostnJ5OJJzmufAYiiiz6A4MsxLvdQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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