SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '38944af9caceb76f27043729171c24be4346ca261e0556900f6693d260770ad2' 
  AND token = 'w9mU+fYkelgZfVO+y29PrilmFlOxSsdQt/sA/jiz9mE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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