SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '93b43388261ab99ee6fe788cc164c279a9014b24f92d4a16e1895e53831541f3' 
  AND token = 'H1rXs/OkoXfNyRtpXUBmNEblB49G9A+SMTiz+vnWM8c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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