SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '7801273f28bd4ccfc92d30c528efddae8f56d1c02cb197527b6faa4b9d4b0dbb' 
  AND token = 'KtKBoKWz+9P08W/DFPaG55IfJYJer5BZbR6zUdLYb+Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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