SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cb4097b3256237cdbc4f0fe574fcde66027b9437167d0555d559262536c1f3d9' 
  AND token = 'F8aTmpJpUVpOGXzv7UkeRGU6CgPOwjmfpM74X4PQ2LE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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