SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '236cfb32f9110d9fb1e16a7fb10954d2bff985f88ea6858f81b4ecab808e2f1d' 
  AND token = 'DBC0KotNoTvygGbRv8ovoNGP08kNlEsLPGLVgRfS3ac=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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