SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '5e657a13db604fcf73861bff521337d021fc64ad5ac10912d5aac8ae5df98ba7' 
  AND token = 'Razg2KI6zAjR2VPw+yuLOrdxNj7kMZPQIZDudRpkJK4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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