SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3e37078dc28a9a812f727fd52b64ebf75ac9c9542986113e03c9c9e8b18e6662' 
  AND token = 'wn+DY/ft9UL2qLVsTBJlidBJIuIv7GcSL4rQxqstxM4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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