SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '070299f287e473e856eeafbcfd2e0311b27b8bc6fb25aac33d2739daa7bf78ac' 
  AND token = 'hBVHgz5ZzUzE4jxJx/hDUyPjUhKn35gl6Z+G1AVtFx8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}