SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5b9223903b6ee0934c7d3dabfc6a2c5548a38e2e584448e1ea91cf2ab31648c5' 
  AND token = 'q6SVBnApLK15+mOVYXTWvhRad1RIpDma1iQaO4jFHXw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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