SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f3d0eb05bebc561e8258007dd3d7e14ba1850ab494b789590dc940e169695b28' 
  AND token = 'wUpRMO9XR8htowj/nVJs/mfX2MRIeOEVJiSO00EWjxg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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