SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cfabe9ba1698a20b667ac42f52c37d9d2b06714a6f363ba1fcc3211820ff293a' 
  AND token = '+E8QAn8FTYQj01z0wJq5qKLDFllGMTuhZB17zKG0RBg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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